Due to their ability to outcompete our native plants, invasive plants are overtaking many of our natural areas. This results in decreased biodiversity not only of plants but also of our native wildlife, birds, and beneficial insects. Invasive plant species have several strategies to outcompete our native plants. These include rapid growth and high reproductive rate.

Autumn is the time of year when gardeners can beat invasive plants at their own game, using one of their competitive advantages against them. Yet another survival tactic that invasive plants utilize is to begin growing very early in the spring and continue to grow late into fall. This gives them the opportunity to outcompete native plants who are dormant during these times. As a result of this adaptive behavior we can get the upper hand at this time of year in our battle with invasive plants, as it is easier to locate and eradicate them in autumn.

During the height of the growing season it can be difficult, in the expanse of green, to identify which plants are invasive. Looking out over your property in late Autumn, however, most of the plants that remain vigorously green are typically non-natives, many of them invasive.

zannah crowe johnson's gardens cedarburg wisconsin
“Due to increased herbicide translocation to the rootzone, applications made after the first frost of the season are significantly more effective than earlier applications.”
-Zannah

In addition to easy identification at this time of year, fall is an effective time to apply herbicide to undesirable plants. Applications of herbicide made after the first frost of the season have been shown to be significantly more effective than earlier applications in controlling Dandelions, Creeping Charlie, and Buckthorn. If plants are actively growing, and daytime temperatures are at least 50 degrees, fall herbicide treatment will be successful.

Buckthorn

For control of Buckthorn it’s most effective to uproot young seedlings. Larger plants can be cut down, then spray or paint herbicide on the cut surface to kill the plant down to the root. This helps avoid re-sprouting from the base. Dig deeper on Battling Buckthorn.

Herbicides for Late Season Invasive Control

  • Bonide Chickweed, Clover & Oxalis Killer
  • Bonide Poison Ivy & Brush Killer
  • Bonide Weed Beater Ultra (effective down to 40 degrees)
  • Bonide Stump & Vine Killer (paint on cut Buckthorn stumps for total control)
beating invasives at their own game fall weed control buckthorn killer